Fibulin 3, also known as epidermal growth factor (EGF)-containing fibulin-like extracellular matrix protein 1 (EFEMP1), is a member of the fibulin family of extracellular glycoproteins, a group of proteins that are widely distributed and frequently associated with vascular and elastic tissues. The fibulin proteins typically contain a tandem array of EGF-like repeats and a fibulin-type COOH-terminal module. Aberrant accumulation of Fibulin 3 in the endoplasmic reticulum of retinal pigment epithelial cells has been shown to be associated with inherited forms of macular degeneration, but the loss of Fibulin 3 expression does not lead to macular degeneration but rather the appearance of hernias due to a reduction of elastic fibers of fascial connective tissue. Recent experiments have shown that expression of Fibulin 3 promotes tumor growth and may thus be a therapeutic target. At least three isoforms of Fibulin 3 are known to exist. This antibody is predicted to not cross-react with other Fibulin proteins.